1. The value of zoo experiences for connecting people with nature;Bruni;Visit. Stud.,2008
2. Zordan, M. (2021, September 05). Progressive Zoos and Aquariums Must Be Part of the World’s Response to COVID-19, Available online: https://www.iucn.org/crossroads-blog/202101/progressive-zoos-and-aquariums-must-be-part-worlds-response-covid-19.
3. ZSL (2022, May 22). Landmarks in ZSL History, Available online: https://www.zsl.org/about-us/landmarks-in-zsl-history.
4. ZSL (2022, May 22). Introducing the Modern Zoo, Available online: https://www.zsl.org/education/introducing-the-modern-zoo.
5. Criteria for the evaluation of zoo research projects;Kleiman;Zoo Biol.,1985